4 files changed, 8 insertions, 8 deletions
diff --git a/src/CabalHelper/Compiletime/Program/Stack.hs b/src/CabalHelper/Compiletime/Program/Stack.hs
index f0dd766..353e8f1 100644
--- a/src/CabalHelper/Compiletime/Program/Stack.hs
+++ b/src/CabalHelper/Compiletime/Program/Stack.hs
@@ -46,11 +46,7 @@ import CabalHelper.Compiletime.Types.RelativePath
 import CabalHelper.Shared.Common
 
 getUnit :: QueryEnvI c 'Stack -> CabalFile -> IO (Unit 'Stack)
-getUnit
-  qe@QueryEnv{qeProjLoc=ProjLocStackYaml stack_yaml}
-  cabal_file@(CabalFile cabal_file_path)
-  = do
-  let projdir = takeDirectory stack_yaml
+getUnit qe cabal_file@(CabalFile cabal_file_path) = do
   let pkgdir = takeDirectory cabal_file_path
   let pkg_name = dropExtension $ takeFileName cabal_file_path
   look <- paths qe pkgdir
@@ -91,7 +87,7 @@ listPackageCabalFiles qe@QueryEnv{qeProjLoc=ProjLocStackYaml stack_yaml}
   return $ map CabalFile $ lines out
   where
     ioerror :: IOError -> IO a
-    ioerror ioe = (=<<) (fromMaybe (throwIO ioe)) $ runMaybeT $ do
+    ioerror ioe = (fromMaybe (throwIO ioe) =<<) $ runMaybeT $ do
       stack_exe <- MaybeT $ findExecutable $ stackProgram $ qePrograms qe
       stack_ver_str
         <- liftIO $ trim <$> readStackCmd qe Nothing ["--numeric-version"]
@@ -116,6 +112,8 @@ listPackageCabalFiles qe@QueryEnv{qeProjLoc=ProjLocStackYaml stack_yaml}
 workdirArg :: QueryEnvI c 'Stack -> [String]
 workdirArg QueryEnv{qeDistDir=DistDirStack mworkdir} =
   maybeToList $ ("--work-dir="++) . unRelativePath <$> mworkdir
+workdirArg QueryEnv{qeDistDir=DistDirCabal{}} =
+  error "workdirArg: TODO: this case is impossible and should not produce an exhaustiveness warning anymore starting with GHC 8.8"
 
 doStackCmd :: (QueryEnvI c 'Stack -> CallProcessWithCwd a)
            -> QueryEnvI c 'Stack -> Maybe FilePath -> [String] -> IO a
diff --git a/src/CabalHelper/Compiletime/Types.hs b/src/CabalHelper/Compiletime/Types.hs
index cded136..e79c812 100644
--- a/src/CabalHelper/Compiletime/Types.hs
+++ b/src/CabalHelper/Compiletime/Types.hs
@@ -32,7 +32,6 @@ import Data.IORef
 import Data.Version
 import Data.Typeable
 import GHC.Generics
-import System.FilePath
 import System.Posix.Types
 import CabalHelper.Compiletime.Types.RelativePath
 import CabalHelper.Shared.InterfaceTypes
diff --git a/src/CabalHelper/Runtime/Compat.hs b/src/CabalHelper/Runtime/Compat.hs
index 0c5a895..1673b7a 100644
--- a/src/CabalHelper/Runtime/Compat.hs
+++ b/src/CabalHelper/Runtime/Compat.hs
@@ -16,6 +16,7 @@
 
 {-# LANGUAGE CPP, BangPatterns, RecordWildCards, RankNTypes, ViewPatterns,
   TupleSections #-}
+{-# OPTIONS_GHC -fno-warn-unused-imports #-}
 
 #ifdef MIN_VERSION_Cabal
 #undef CH_MIN_VERSION_Cabal
diff --git a/src/CabalHelper/Runtime/HelperMain.hs b/src/CabalHelper/Runtime/HelperMain.hs
index b4ba6cc..a3119e5 100644
--- a/src/CabalHelper/Runtime/HelperMain.hs
+++ b/src/CabalHelper/Runtime/HelperMain.hs
@@ -16,7 +16,7 @@
 
 {-# LANGUAGE CPP, BangPatterns, RecordWildCards, RankNTypes, ViewPatterns,
   TupleSections #-}
-
+{-# OPTIONS_GHC -fno-warn-unused-imports #-}
 {-  # OPTIONS_GHC -Wno-missing-signatures #-}
 {-  # OPTIONS_GHC -fno-warn-incomplete-patterns #-}
 
@@ -512,6 +512,7 @@ componentOptions' (lbi, v, distdir) inplaceFlag flags rf f = do
 #else
                                [] -> removeInplaceDeps v lbi pd clbi
 #endif
+                               _ -> error $ "invalid flags: " ++ show flags
            opts = componentGhcOptions normal lbi bi clbi' outdir
            opts' = f opts
 
@@ -686,6 +687,7 @@ combineEp (Just ChSetupEntrypoint) e = e
 combineEp (Just (ChLibEntrypoint es1 os1 ss1))   (ChLibEntrypoint es2 os2 ss2) = (ChLibEntrypoint (nub $ es2++es1) (nub $ os2++os1) (nub $ ss2++ss1))
 combineEp _                                    e@(ChExeEntrypoint  _mi _os2)     = error $ "combineEP: cannot have a sub exe:" ++ show e
 combineEp (Just (ChExeEntrypoint  mi os1))       (ChLibEntrypoint es2 os2 ss2) = (ChExeEntrypoint mi  (nub $ os1++es2++os2++ss2))
+combineEp me e = error $ "combineEp: undhandled case: " ++ show (me, e)
 
 -- no, you unconditionally always wrap the result in Just, so instead of `f x = Just y; f x = Just z` do `f x = y; f x = z` and use f as `Just . f`